Means and method of refrigeration



Oct. 11, 1932. B, RANDEL I 1,882,257

MEANS AND METHOD REFRIGERATION Filed May 18, 1951 2 Sheets-Sheet 1 MEANSAND METHOD OF REFRIGERATION Filed May 18. 1931 2 Sheets-Sheet 2 PatentedOct. 11 1932 BO FOLKE RANDEL, OF SAN DIEGO, CALIFORNIA MEANS AND METHODOF REFRIGERATION Application filedMay 18, 1931, Serial No. 538,090.

My invention relates to refrigerating means and apparatus of theso-called vacuum type. In this type of apparatus a refrigerating medium,as water, is evaporated in a vacuum, this evaporation causing heatabsorption and refrigeration.

My invention is based upon formation of such a vacuum in a very simplemanner. The following descriptive experiment will illustrate this simplemanner of creating a vacuum.

Assume a bottle completely filled with water, from which all air hasbeen driven out. Now, assume this bottle turned upside ll down and withthe opening connected to a liquid pump.

Now, if pump is started, the water will be pulled out of the bottle anda space of vacuum will be created. As the water is Withdrawn,

pressure is reduced and evaporation of water will take place to fill thespace above the surface. The evaporation will cause heat absorption andcooling of the remaining water In my apparatus I do this continuouslyand also remove the vapors formed, and once a certain point is reac ed,condense the va pors removed and return same to the evaporator in liquidform, again to be evaporated.

Any liquid may be used in my apparatus,

80 but for simplicity of description,-water will be assumed to be themedium used. Other liquids which may be mentioned as suitable arealcohols, ethers, hydro-carbons, etc., and such liquids may beespecially suited where a lower temperature than 32 degrees Fahrenheitis required.

In Fig. 1, I illustrate in diagrammatic form an arrangement suitable tomy purpose, and in Fig. 2, I illustrate a slight modification of onepart of the apparatus. In Fig. 3 I show a structural modification ofFig. 1. The several parts are conventional and may i be constructed inmany different ways.

The principal arts of my apparatus are evaporating cham er 1, condensingchamber 2, circulating pump or compressor 3, and vapor entraining column4.

Assume water as refrigerating agent, the

operation of the apparatus is now as fol 53 lows Before pump 3, drivenby motor 3a is started, water fills the apparatus up to level A. All theair is removed so that space above this line A is filled with watervapor under the pressure as a resultant of the temperature. The entireapparatus is sealed so as toprevent any inflow of air, and anadvantageous construction will be to also enclose the motor with thesealed parts. If we assume a temperature of 70 degrees F. throughout theparts, then the vapor pressure in the vapor space will be approximately0.3626 lbs. absolute, thus the apparatus operates under an initialvacuum of 29.18 inches of mercury.

In larger installations, chamber 2 may be vented in such a manner as toprevent inflow of air or the breaking of the vacuum, but with provisionto discharge vapors or liquid as desired when pressure in this chamberis above pressure outside of same. Also, a separate vacuum pump may beadded to maintain necessary vacuum and remove any air which may leakinto the system. In the following description it is assumed that theapparatus is sealed and absolutely tight and with all the air removed,but I do not limit the construction to this arrangement. The pump 3,which maybe of any construction, centrifugal, gear, rotary,-etc., is nowstarted. Liquid below line A in chamber 1, pipe 4 and pipe 6 will betransferred over to chamber 2. This chamber communicates through pipe 5and nozzle 8 with entraining column 4. Nozzle 8 discharges throughVenturirestriction.9 and liquid passing through 5 and 8 will entrainvapors in chamber 7 pulling same along through column 4 to suction pipe10 of pump 3.

Now, nozzle 8 is restricted so as to permit building up of the pressurein-condensing chamber 2 sufficient to compress vapors present there, andby cooling same by cooling coil 2a, condensing same to liquid stat It isseen that by this action all the vapor may be condensed inchamber 2,thus filling same with liquid to level B. The liquid is thus withdrawnfrom chamber 1 and the cubical contents or volume of the diiferentchambers and interconnected ipes are so figured that when chamber 2,p1pe 5 and entraining column 4 are entirely, or nearly so, filled withliquid, the level A above chamber 1 is lowered to level G. The liquidbeing practically incompressible this level C will be maintained, andany addition to the liquid in the combination 2, 4 and 5, will forcethis additional liquid through pipe 11 with seal 11aand into chamber 1,notwithstanding pipe 11 is on suction side of pump.

When this phase of the operation is reached three conditions will arise.

F irstno further liquid can be drawn from chamber 1 over to suction ofpump 3.

Secondall the liquid handled by the pump will circulate through pipe 12,chamber 2, pipe 5, entraining column 4 and back to pump through pipe 10.

Third-the removal of part of the liquid from chamber 1 will lower thepressure in same and will cause evaporation from the remaining liquid.If we assume that the vapor volume in 1 and connecting pipe 6, and alsospace 7 is enlarged by the removal of liquid to ten times its originalvolume, which may be easily arranged for, then the pressure beingpractically in inverse proportion to the volume, this pressure will dropfrom the original, or from 0.3626 to 0.03626 lbs. abs., provided ofcourse no evaporation of the liquid took place. However, as soon aspressure drops evaporation will take place with absorption of heat fromthe liquid, and from the surrounding objects, which evaporation willcause increase of pressure to correspond to the desired temperature ofthe object to be cooled. Using water as agent, temperature may reach 32degrees with a drop of pressure to 0.0886 lbs. abs. per sq. in.

Vapors formed in chamber 1 will pass through pipe 6 to chamber 7, thereto be entrained with the liquid coming through pipe 5. The entrainingcolumn may be surrounded with cooling jacket 40 where cooling water isused to assist in condensing the vapors. Vapors not condensed here, willbe condensed in condensing chamber 2 under the increased pressure there.

Now, any vapors pulled in at 9 and condensed in 4 or 2 will add to theliquid on the high pressure side and will force a. similar amountofliquid through pipe 11 to evaporating chamber 1, thus maintaining aconstant supply of new liquid to be evaporated. The entraining nozzle 8may discharge downwards as shown, pulling along va ors which will traveldownwards with the iquid similar to air bubbles in liquid compressorsand barometric condensers, or the nozzle may discharge upwards orhorizontally as desired.

I have shown in evaporatlng chamber 1 capillary tubes or columns 1a.These tubes or columns are made of porous-material as unglazed tile, andthe purpose is to increase the area of evaporating surface by capillaryaction. Liquid will be sucked upwards into the material of theseelements and thus increase the area of liquid surface.

In Fig. 2, I show a modification of evaporating chamber 1 to increasethe area of liquid surface. Liquid drawn out of the chamber through pipe11 is checked by conventional ball check 13 preventing flow back to thechamber through this line. Liquid flowing back to chamber must flowthrough pipe 17, ball check 14 and over pans 16 inside said chamber 1.Any suitable check valge arrangement to direct the liquid can be useMany other arrangements of the apparatus may be arranged and I includeall such in my invention to perform the work of refrigeration accordingto my principle of operation.

It is to be noted that although two dif- :Eerent pressure zones arepresent during operation, a higher pressure and a lower pressure, noexpansion valve is used. Refrigerant is fed to low pressure zone fromhigh pressure zone without the use of expansion valve. The apparatus maybe built without the use of any valves, float or pressure operated. Theprinciple of feeding liquid refrigerant to an evaporator is entirelynovel and not employed in any other refrigerating apparatus.

In Fig. 3 I show a slight structural modification. Parts 5, 6, 7 and 8of Fig. 1 are shown in a lower position and below the liquid level A.The parts moved down are denoted 5A, 6A, 7A, 8A and 45A, andfunctionsimilar to 5, 6, 7, 8 and 4b as shown in Fig. 1. Thismodification is indicated-that my apparatus may be constructed in manydiflerent'ways to carry out the same principle of operation.

I claim I '1. A method of refrigeration comprising the removal of partof a'liquid contained in a vessel, thus creating a space of loweredpressure in said vessel, evaporating. part of the liquid remaining insaid vessel into said space of lowered pressure with resultantabsorption of heat, passing said produced vapor to a condensing space,liquefyingsaid vapors and returning liquid to said vessel to make up forthe evaporation in said vessel.

2. Creating a low pressure in an evaporating vessel in connection with acondensing vessel by transferring part of aliquid from the first to thesecond vessel, evaporating the liquid remaining in said evaporatingvessel taining a liquid to be evaporated, a condensing chamber withmeans attached to cool and condense a vapor, communication means be-=tween said evaporating chamber and said con densing chamber, pump meansto transfer liquid from a lowered pressure in said evaporating chamberagainst a raised pressure in said condensing chamber through saidcommunication means, means to pass liquid from said condensing chamberthrough a vapor entraining chamber, communication means between saidvapor entraining chamber and vapor space of said evaporating chamber,means to mix and entrain vapors produced in said evaporating chamber inthe liquid passing through said entraining chamber and means to passsaid mixture of vapor and liquid to suction side of said pum means andfurther means to return to sai evaporating chamber sufficient liquid tocompensate for loss due to evaporation in same, thus maintaining aconstant liquid level in said evaporating chamber during operation ofthe apparatus.

4. A method of refrigeration removing vapors from an expansion space byentraining same in a moving liquid column, condensing said vapors andreturning refrigerating liquid to said expansion space by volumetricdisplacement and without the employment of an expansion valve betweenthe condensing space and the evaporating space.

5. A refrigerating apparatus of the vacuum type, a condensing space andan evaporating space, means to transfer vapors from said evaporatingspace to said condensing space by entraining said vapors in a liquid,and means to return refrigerating medium from said condensing space tosaid evaporating space by volumetric displacement.

6. In a' refrigerating apparatus of the vacuum type, an evaporatingspace and a con- (lensing space and means to create a lowered pressurein said evaporating space by transferring liquid from said evaporatingspace to said condensing space, thus increasing the volume of the vaporspace in said evaporating space.

7. A method of refrigeration, transferring liquid from an evaporatingspace-to a condensing space thus increasing the volume of the vaporspace in said evaporating space,

causing evaporation of the remaining liquid,

and constantly maintaining such evaporation by removing the vaporsproduced by entraining same in a moving body of liquid.

In testimony whereof, I have hereunto set my hand at San Diego,California, this 14th day of May, 1931.

' BO FOLKE RANDEL.

